Unconditional two-locus nonparametric linkage analysis
We discuss different aspects of unconditional two-locus nonparametric linkage (NPL) analysis with special emphasis on gene-gene interaction. We interpret this as identical-by-descent (IBD) sharing correlation between two disease loci both having marginal effect. We relate this to the concept of two-locus NPL score functions, the possible importance of using a composite rather than a simple null hy